The objective is to evaluate "neighborhood effects" in community trials for cardiovascular disease (CVD) prevention. During the 1980s, the NHLBI/NIH funded three community trials to test programs aimed at reducing CVD risks. While each study reported favorable risk factor changes, many overall net differences between treatment and control sites were modest and/or statistically insignificant. New research suggests that these analyses may mask important within-site neighborhood-wise endpoint differences. It may be that (1) "place," above and beyond individual level measures, influences CVD-related behaviors and (2) overall program outcomes may be confounded by neighborhood level influences. This study employs rich and existing data from the (1) Pawtucket Heart Health Program (PHHP) and (2) the 1980 and 1990 decennial censuses. Multilevel statistical methods and a geographic information system (GIS) are used for analyses. Briefly, the specific aims are to: Determine the extent to which individual-level CVD related variables vary by neighborhood; Identify neighborhood-level predictors of CVD risk after adjusting for individual-level measures; Examine neighborhood-wise endpoint trends; Analyze dose effects (i.e., intervention process) in terms of neighborhoods; Evaluate the effect of different neighborhood definitions on findings; Find best methods for handling demographic trends when census data are gathered decennially; Advance multilevel and GIS methodologies in cardiovascular epidemiology; Contribute to an epidemiologic theory of "place." This cost-effective three year study is significant, innovative and timely. It will advance the multidisciplinary substantive understanding and methodological tools necessary for public health practice in the twenty-first century.